vimeo/psalm

MethodSignatureMismatch - Argument 1 of DateTime::__unserialize has wrong type 'mixed', expecting 'array<array-key, mixed>' as defined by DateTimeInterface::__unserialize

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#8,957 opened on Dec 20, 2022

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 (7 comments) (0 reactions) (0 assignees)PHP (5,369 stars) (668 forks)batch import
Help wantedeasy problemsgood first issueinternal stubs/callmap

Description

Running on PHP 8.2, I have this code:

I cannot reproduce it on psalm.dev, but I assume it has to do with stubs.

<?php

declare(strict_types=1);

namespace App\Extension\Type;

use DateTime as PHPGlobalDateTime;

class DateTime extends PHPGlobalDateTime
{
    public function __toString(): string
    {
        return $this->format('U');
    }
}

Getting:

ERROR: MethodSignatureMismatch - src/Extension/Type/DateTime.php:10:7 - Argument 1 of DateTime::__unserialize has wrong type 'mixed', expecting 'array<array-key, mixed>' as defined by DateTimeInterface::__unserialize (see https://psalm.dev/042) class DateTime extends PHPGlobalDateTime implements StringableDateTimeInterface

Contributor guide

Tech stack
php
Domain
tooling
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
basic PHP knowledgeunderstanding of Psalm stubs
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
50
Research direction
The issue is a false positive in Psalm's stubs for DateTime:: unserialize. The fix likely requires updating the stub definition for DateTimeInterface to correctly reflect the signature. Check the stub files in the repository, particularly the ones for DateTime and DateTimeInterface. Maintainer input may be needed to confirm the expected behavior.